The present invention relates to fluent material handling and more specifically to an apparatus and method for removing and replacing fluid in a system in a vehicle.
Vehicles utilize a number of fluid systems to operate components. A significant vehicular fluid system is a hydraulic brake system in which force applied to a brake pedal is amplified and transmitted to brake drums or disks via a hydraulic system. Therefore, the present invention will be discussed in the context of a hydraulic automotive brake system but is not so limited. Other automotive fluid systems include, for example, power steering, oil, and automatic transmission systems.
The basic functions performed by a system for removing and replacing vehicle hydraulic fluid include removing old hydraulic fluid from a master cylinder, vacuuming out old fluid through bleeder valves, refilling the brake fluid lines and master cylinder while keeping moisture and other contaminants from entering the new fluid and keeping air out of the brake fluid lines. The old fluid must be delivered to a suitable waste container. Such functions have been performed by prior art system.
Prior systems, however, do not address considerations that have become more significant in view of the increasing sophistication of brake fluid and brake systems, federal regulations, and quality assurance. It is desirable to have a hydraulic fluid changing apparatus that can require that input information is provided to assure that the container of brake fluid being utilized is appropriate for use. It is desirable to assure that the container from which the brake fluid is drawn has not been refilled and reused. This can prevent the use of counterfeit, contaminated, or inappropriate products. The United States Department of Transportation has established grades such as DOT 3, DOT 4, DOT 5, and DOT 5.1. Each has a different formula and characteristics. DOT 3 fluid is the least expensive grade, most widely available and most widely used. DOT 4 fluid is more expensive. DOT 4 fluid has a higher boiling point making it more suitable for high-performance applications such as Automatic Brake Systems (ABS). Capacity to recognize that the appropriate fluid is being used in a particular car is a desirable capability.
While prior systems have accounted for proper disposal of used brake fluid, disposal of remaining new, clean brake fluid has not been addressed. However, clean brake fluid is a hazardous material in terms of disposal regulations just as well as used brake fluid. It is further desirable to provide a system that communicates many different conditions to a service technician to maximize ease of use of the apparatus and minimize improper handling of new or used hydraulic fluid.
Briefly stated, in accordance with the present invention, there are provided a method and apparatus for removing and replacing fluid in a vehicle fluid system in which a fluid container is modular with respect to an apparatus including pump means for evacuating old fluid from the system and pumping new fluid into a system. An adapter is used to interface fluid from the apparatus to the vehicle fluid system to maintain a closed fluid system. Consequently, contaminants are prevented from entering the vehicle fluid system. The apparatus includes a reader to read indicia on a container of new fluid. The indicia may, for example, comprise a bar code. The apparatus is provided with a memory and information indicative of approved indicia so that the contents of the container will not be dispensed by the apparatus unless an approval was generated in response to reading the indicia.
In a preferred form, basic functions such as draining a master cylinder of old fluid and emptying waste from the apparatus are performable without an approval. The modular container is attached to the apparatus so that contents are drawn therefrom without waste or spillage. The container is preferably received in a protected enclosure. The apparatus preferably provides to a technician utilizing the system condition-indicative information, for example, an indication when the fluid in the container has been emptied. Also, at the completion of filling the closed system, pressure in the system cylinder fill line is reduced when service is interrupted or completed. The apparatus also contains a waste tank for receiving drained fluid, and can also empty an incompletely used clean container into the waste tank. A specific pump empties the waste fluid from the waste tank to an external disposal vessel. The apparatus also controls times and operating parameters of ongoing operations.